Downlink Analysis in Unmanned Aerial Vehicle (UAV) Assisted Cellular Networks With Clustered Users

Abstract

The use of unmanned aerial vehicles (UAVs) operating as aerial base stations (BSs) has emerged as a promising solution especially in scenarios requiring rapid deployments (e.g., in the cases of crowded hotspots, sporting events, emergencies, natural disasters) in order to assist the ground BSs. In this paper, an analytical framework is provided to analyze the signalto-interference-plus-noise ratio (SINR) coverage probability of unmanned aerial vehicle (UAV) assisted cellular networks with clustered user equipments (UEs). Locations of UAVs and ground BSs are modeled as Poison point processes (PPPs), and UEs are assumed to be distributed according to a Poisson cluster process (PCP) around the projections of UAVs on the ground. Initially, the complementary cumulative distribution function (CCDF) and probability density function (PDF) of path losses for both UAV and ground BS tiers are derived. Subsequently, association probabilities with each tier are obtained. SINR coverage probability is derived for the entire network using tools from stochastic geometry. Finally, area spectral efficiency (ASE) of the entire network is determined, and SINR coverage probability expression for a more general model is presented by considering that UAVs are located at different heights. Via numerical results, we have shown that UAV height and path-loss exponents play important roles on the coverage performance. Moreover, coverage probability can be improved with smaller number of UAVs, while better area spectral efficiency is achieved by employing more UAVs and having UEs more compactly clustered around the UAVs.Index Terms-Unmanned aerial vehicle (UAV), cellular networks, SINR coverage probability, Poisson point process, Poisson cluster process, Thomas cluster process, stochastic geometry.

Multi-layer Unmanned Aerial Vehicle Networks: Modeling and Performance Analysis

“…Recently, the researches on the ANs, which is the wireless networks consisting of multiple UAVs, have been presented in [11]- [22]. For those works, the stochastic geometry, which is a widely-used tool for randomly distributed nodes [23], has been used.…”

“…The Poisson point process (PPP)-based ANs model is presented and studied in [11]- [13], and the LoS and non-line of sight (NLoS) channels are considered for the air-to-ground (A2G) communications in [11] and [12]. Furthermore, the research on the coexistence of ANs with the terrestrial network is presented in [16]- [22]. In these works, the terrestrial network is modeled by a PPP and the distribution of UAVs is modeled by 3-D PPP [16]- [18] and 2-D PPP [19], [20].…”

“…The multiple layer structure can also be useful and required for better resource management and reliable communications, especially when the number of UAVs and UAV-related applications increase. Recently, the multiple layer structure for UAV communications has been considered in [14], [15], and [22]. In [14] and [15], the UAVs are used as relays [14] or downlink base stations to improve the downlink spectral efficiency [15].…”

“…In [22], the spectral efficiency of multiple layer structure AN was analyzed, by focusing on the communications of ground base stations, which are assisted by UAVs. However, in [22], only the performance of the single layer AN case is provided in the simulation results and the communication between UAVs are not considered, which fails to fully explore the efficient design of the multiple layer AN. Therefore, in this paper, we consider the multi-layer aerial network (MAN), and provide a framework for the efficient design of the MAN.…”

On the Effect of Temporal Correlation on Joint Success Probability and Distribution of Number of Interferers in Mobile UAV Networks

“…Depending on the system model, different point processes from stochastic geometry have been used in the existing literature to model a UAV network and study downlink communication performance in different scenarios (e.g. in [1], [2]- [4], [5]). However, all of the existing work on static and mobile UAV scenarios only consider one time slot.…”